Process of flocculating negatively charged emulsoids from a disperse medium



Patented Jun 20,? 1933 UNITED STATES PATENT OFFICE QLIVER M. URBAIN, OFCOLUMBUS, OHIO, ASSIGNOR TO QHARLES H. LEWIS, OF

' HARPSTER, OHIO PRQGESS OF FLOCCULATING CHARGED EMULSOIDS FROM ADISPEBSE MEDIUM 7 v No Drawing.

incide with the'isoelec'tric point. The critip w cal hydration point isthat point in the hydration of the emulsoids at which they willfiocculate, providing they are at their critical potential.

An important "feature of the present invenm tion, therefore, relates tothe desolvation or dehydration of the emulsoids in the disperse me um.Specifically, the invention contemplates the displacement of theadsorbed sol- 25 vating water film or the emulsoids by molehas a greaterafinity than it has for the water molecules of the solvating film. Inother words, the invention contemplates the remevncrnena ct preferentialadsorption. When the'emulsoids are negatively charged, the watermolecules of the solvating film are oriented over the surface'of thenucleus of the emulsoid with the positive H ends of the moleculespointed inwardly and tenaciously held by adsorption. lln order todisplace these water molecules, it is necessary to employ moleculeswhich have one end of suclrpolarity that it will be more'stronglyadsorbed than the H end of the water molecule, so that preferentialadsorption will take place. It is further essential that the negativeends of the molecules used to displace the water molecules must not besubj ect' to solvation. Furthermore, the water displacing molecules mustnot be dissociated any appreciable ex tent in the water of the dispersemedium.

It is, of course, possible to flocculate emulm soids without desolvationor dhydrationby cules for which the nucleus of the erhulsoidal of thesolvating water film by the phe polycyclic radical and maybe 1 or more.

Application filed June 7, 1932. Serial No. 615,949.

salting out but in so doing, enormous quantities of salts are reguired,in comparison to the quantity require when the emulsoids are firstde-hydrated. F or instance, to effect flocculation of agar agar, aneinulsoid, one mol per liter of anhydrous M SQ; is required. If,however, the agar agar is first desolvated or dehydrated, it can beflocculated by the addition of one millomol per liter of the same salt.The importance, therefore, of desolm vating or dehydrating the emulsoidsbecome at once apparent Accordi g to the present invention, thesolvating 318M381 film of the emulsoids is displaced hy incorporating inthe disperse medium compounds made up of the esters of aliphatic acidswith mono or polyhydroxy derivatives of polycyclic compounds. The estersof aliphatic acids with mono or polyhydroxy derivatives of polycycliccompounds are formed by the reaction of aliphatic acids with the mono orpolyhydroxy derivatives of polycyclic compounds, by the elimination ofone or more molecules oil-L0 (one 1 acidic H of the aliphatic acid toone 0H of E5 the hydroxy derivative of the polycyclic compound), andhave the general formula:

0 (JR-( Ar \O a in which, is an alipahtic hydrocarbon radical, Ar is apolycyclic radical, substituted or unsubstituted, n is the valence ofthe A specific group of compounds well adapted for use in the processare those made up of the esters of fatty acids with the mono orpolyhlydroxy derivatives of polycyclic compoun s. i

A specific example ofthe formation of a suitable compound under theabove general formula-using analiphatic acid, not of the fatty acidgroup, is shown below between acrylyl chloride (chloride of an aliphaticas acid) and naphthol which gives'naphthyl acrylate.

A specific example of theformation of a compound under the above generalformula using an ester of a fatty acid, namely caproyl chloride, and2-naphthol to form fl-naphthyl caproate, is as follows:

The above reactions are effected in the presence of around 10% KOH andat a temperature of around 10 C.

All compounds conforming to the general formula containing a. carbonchain not ex-' ceeding eight carbon atoms will function advantageouslyin the process. The polycyclic residue or radical due to its union withthe aliphatic acid, as well as to the plurality of double bonds is polarin nature and possesses many individual centers of polarity. Thesefactors assure strong individual centers of polarity. These factorsassure strong adsorption of the molecule, and render it preferentiallyadsorbed over the positive H of the water molecules of the solvatingfilm on the emulsoid. The negative end of the molecules of the compound,namely the acid residue, which is exposed to the aqueous solution afterorientation is not subject to solva tion.

' The above specific examples of compounds formed under the generalformula are compounds resulting from the use of a mono ydroxy derivativeof the polycyclic compound.

In some instances it may be desirable to employ a compound fordesolvating or dehydrating emulsoids which have greater polarity andsolubility than possessed by compounds formed with mono hydroxyderivatives of polycyclic compound. Compounds having increased polarityand solubility can be obtained by substituting hydroxy groups for Hatoms on the benzene nucleus of the polycyclic structure. For example,if it is found that the polarity and solubility of say Q-naphthylcaproate is insufiicient for the desolvation of a specific emulsoid, itis possible to prepare a compound possessing increased polarity andsolubility by using in the formation of the compound, the polyhydroxyderivative 1.4 dihydrocynaphthalene.

By treating the 1.4 dihydroxynaphthalene with caproyl chloride, mol formol, in the presence of 10% KOH and at a temperature around 10 0. thereis obtained 4-hydroxyl-naphthyl caproate the reaction being as follows oI lHn-J cmltooo on 1101 cl my l-naphthyl propionate.-.. C H,.COO.C LHl-anthryl valerate "CJI GOQC H 3-phenanthryl caproizte- CBH; .COO.C H,

While the ste of desolvating emulsoids to facilitate their occulationhas wide adaptation,, it is of especial utility with respect to thetreatment of organic waste 1i ui 'such as sewage and industrial wastes.t will be appreciated, of course, that the step of desolvating theemulsoid is not aldne sufiicient to effect its flocculation.Accordingly, the

not only the initial step of desolvating the emulsoids by theincorporation in the disperse medium of a compound as hereinbeforedescribed, but also comprehends the additional steps of controlling thepH of the solution to permit the flocculation of the desolvated ordehydrated emulsoids b a suitable electrolyte and the final coagu ationof the fiocculated material;

A specific illustration of the application of the process is as follows:Assuming that it is desired to remove the emulsoid content from a wasteliquid, which emulsoid content has a ten day bio chemical oxygen demandof 250 to 300, the desolvating or dehydrating compound, for examplel-naphthyl butyrate should be added in liquid form in an amount from 40to pounds per million allons of waste. Thereafter, the waste s ould beagitated for a period of two to four minutes and have incorporatedtherein sufficient calcium hydroxide to bring thesame to the requisitepH range for the efiicient operation of the electrolyte i. e. to a rangeof 8.5 to 9.5. The electrolyte is then introduced with agitation, whenferric chloride is used as electrolyte, 80 to 10,0 ounds per millionallons of waste should Eeemployed. Folowing introduction of theelectrolyte, the fioccu ated material may be coagulated by theintroduction of. an appro riate amount of a suitable coagulant, such orexample as alu-- minum sulp ate or ferrous sulphate.

Of course, the quantity ofthe compound 1 complete process offlocculation comprehends H g 40 ester of a fatty acid with a polyhydroxydetea comprising incorporating in the disperse menecessary to desolvateor dehydrate the incorporating calcium hydroxide to raise the emulsoids,will vary with the concentration pH of the solution to from 8.5 to 9.5adding of the emulsoids in the liquid to be treated. an electrolyte withfurther agitation and To determine the exact amount of the definallyeflecting coagulation. solvating or dehydrating compound to em- OLIVERM. .URBAIN. 79

ploy, it is only necessary to make up a solu- 'tion of the compound ofknown strength, and add this solution to a known volume of the emulsoiddispersion in gradually increasing amounts and check the reading on aneph- 76 elonieter with a colorimeter attachment, until no furtherturbidity increase is noticed. This will be the point at whichdesolvation A or dehydration is complete, and the necessary quantity ofthe compound required can thus be computed from the known volume of theknown strength solution of the compound used in the experiment.

What I claim as my invention is: 1. In a process for flocculatingnegatively 85 charged emulsoids the step which comprises incorporatingin the disperse medium a compound madeup of an ester of an aliphaticacid with an hydroxy derivative of a polycyclic compound. I 2. ln aprocess for flocculating negatively charged emulsoids the step whichcomprises incorporating in the disperse medium a compound made upof anester of an aliphatic v acid with a polyhydroxy derivative of a polyeacyclic compound.

3. In a process flocculating negatively charged emulsoids the step whichcomprises incorporating in the. disperse medium an.

ester of a fatty acid with an hydroxy derivaice tive of a polycycliccompound.

d. In. a process flocculating negatively charged emulsoids the stepwhich comprises incorporating in the disperse medium an rivative of apolycyclic compound. v

5. In a process fiocculating negatively. charged emulsoids the stepwhich comprises incorporating in the disperse medium 7 naphthylacrylate. Rm 6. In a process fiocculating negatively charged emulsoidsthe step which comprises incorporating in the disperse. medium alnaphthyl butyrate.

) 7. A. process for flocculating a negatively m5 charged emulsoid from adisperse medium comprising incorporating in the disperse mediu an esterof an aliphatic acid with an hydroxy derivative of a polycycliccompound,

then agitating, incorporating calcium hy- 51% droxide to raise the pH ofthe solution to from 8.5 to 9.5 addin an electrolyte with furtheragitation and nally efi'ecting coagulation. i

C0 8. A process for flocculating a negatively charged emulsoid from adisperse medium dium a compound made up of an ester of an aliphatic acidwith a polyh droxy derivative of a polycyclic compoun then agitating,

